1. Field of the Invention
The present invention generally relates to clamps, and more particularly, relates to straight-line action pneumatic power clamps.
2. Description of the Related Art
Power clamps have been known for many years in the prior art. There are numerous varieties of power clamps, such as hold down action power clamps, straight-line action power clamps, heavy-duty toggle clamps, etc. The power clamps generally are used for higher force applications, such as holding of automobile bodies during manufacturing thereof, securing large work pieces to work tables, securing large doors or other covers, such as those found on large trucks. Therefore, the durability and reliability of the clamp is important to the manufacturers who are forced to shut down manufacturing lines if a clamp fails.
Many of the prior art power clamps include a cylinder connected to offset link arms. The offset link arms are attached to a base member. During operation of the prior art power clamps in the manufacturing environment, such as those found in the automotive industry, weld slag and other debris can contaminate the clamp thus reducing its reliability and shortening its life cycle in the manufacturing environment. Furthermore, the use of the open link design power clamps may require protective shielding to be placed around the linkage of the clamp, to try and prevent any damage to the linkage of the clamp by spurious contaminates or collisions by other equipment.
Therefore, there is a need in the art for an enclosed unitized body straight-line power clamp.
Furthermore, there is the need in the art for a power clamp that will repel weld slag, thus increasing the durability of the clamp in the manufacturing environment. There is also a need in the art for a lower cost and easier to manufacture clamp capable of operating in hazardous environments while having high holding capacities.
One object of the present invention is to provide an improved enclosed power clamp.
Another object of the present invention is to provide an improved power clamp that uses a unitized body that will provide a piston rod support therein.
Yet a further object of the present invention is to provide a power clamp that will have all link arms within the clamp mechanism flat, thus removing any offset bends.
Still another object of the present invention is to provide longer support throughout the stroke of the clamp for the plunger mechanism.
Still another object of the present invention is to provide a clamp that uses the same size interior pins to connect the link arms, thus reducing the costs and complexity of manufacturing the clamp.
Still another object of the present invention is to provide a clamp that is more reliable and resistant to weld splatter and the like in the manufacturing environment.
To achieve the foregoing objects the power clamp according to the present invention is disclosed. The power clamp includes a unitized body having a bore in one end thereof A piston is arranged within the bore and is axially slidable therein. An end cap is secured to the body on the end having the bore. The clamp also includes a plurality of first links connected to the piston and at least one second link connected to the first link at a pivot point. The power clamp further includes a plunger arranged within an orifice of the body. The plunger is also connected to the second link. A plurality of identically sized pins connect the links to one another. The clamp also includes side plates, which are connected to the body to enclose the clamp linkage mechanisms within the body of the power clamp.
One advantage of the present invention is that it provides a unitized and enclosed clamp body thus increasing resistance to weld splatter and durability of the clamp in the clamping environment.
Still another advantage of the present invention is that the pins used to connect the link arms within the clamp mechanism are identical in size thus reducing manufacturing costs and complexity of building.
Still another advantage of the present invention is that all link arms are flat and do not have any offset bends, thus reducing costs of the clamp and time in repairing or replacing such parts, while also increasing the strength of the clamp.
Still another advantage of the present invention is that the clamp has a plunger that is supported throughout the entire stroke of the clamp by a longer support mechanism within the body.
Still another advantage of the present invention is that the power clamp piston rod has support by the unitized body without the need for a rod bearing as found in prior art power clamps.
Still another advantage of the present invention is that the piston rod includes a seal that seals in both directions and carries grease away from the piston cylinder.
Still yet another advantage of the present invention is the use of a breather area along the piston rod to prevent pressure buildup inside the clamp and accidental expulsion of internal lubricating grease.
Other objects, features, and advantages of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.